Hop-Up replacement
 

The hop-up unit on my M4 is in need of replacement and I was wondering if there is a hop-up unit that I could order online which comes pre-assembled, so all I would have to do is insert my barrel into it.

If so, Could anyone post a link or name a model I could look into getting.

Thanks.

No, because somewhere along the line in shipping or elsewhere, the small nub inside would fall out.

True, Maybe i should have made myself a bit more clear.
I meant assembled as in, the hardware (minus sleeve and nub)
Just looking to purchase a hop-up chamber with adjustment gears and o-rings pre-assembled.

It takes about 30 seconds to assemble, not sure what the problem is?

It may look daunting at first, but it seriously is a cake walk after the first try as long as you are patient.

Taking your time is key.

There's plenty of videos online showing it step by step.....if you can replace a bettery, you can replace a hop-up. Just don't forget the lube......everything works better with lube.

A dab of silicon gel holds that littel nub in place nicely while the barrel is going in.